The present invention relates, in general, to therapeutically effective pharmaceutical compositions containing plant essential oil compounds, and methods for using same for prophylactically or therapeutically treating of soft tissue cancers in mammals, including humans, such as, for example, breast cancer.
Breast cancer is a proliferative disease of mammary epithelial cells and estrogen has been shown to stimulate cell proliferation of these cells both in culture and in mice (Soto and Sonnenschein, 1985; Osborne, 1981). Xenoestrogens have been proposed to stimulate cell proliferation through binding and activating estrogen receptors (ERs) (Miller et al., 1993; Hoffman, 1992). The incidence of breast cancer has been steadily rising during the past two or three decades, a trend characterized by increasing rates among estrogen-responsive tumors, by continuing increases among older women, and by growing numbers in both developed and developing countries (Harris et al., 1992). Between 1973-1980, the incidence of breast cancer in the United States increased a modest 8% among women under 50 years of age, while it rose 32.1% among women in the age group of 50 years or older (Reese et al., 1991). This upward shift is consistent with the historical pattern of accumulation of organochlorine insecticide residues (xenoestrogens) in the environment (Mussalo-Rauhamaa et al., 1990; Wolff et al., 1993; Davis et al., 1993). Breast cancer is also the second leading cause of cancer deaths in women and it is estimated that in 1998, there will be an additional 43,900 deaths due to breast cancer. Environmental estrogens or endocrine dismptors have been suggested to play a role in the etiology or promotion of breast cancer (Davis et al., 1993; Dewailly et al., 1994). Experimental evidence reveals that xenoestrogens affect estrogen production and metabolism and are among the risk factors that cause breast cancer (Nelson et al., 1978; Berthois et al., 1986; Henderson et al., 1993; Jobling et al., 1995; Dees et al., 1997). Most of the known risk factors for breast cancer, which at least account for 30% of cases (Henderson et al., 1993) are linked with total life-time exposure to reproductive chemicals such as estrogen and xenoesrrogens.
It appears evident that soft tissue cancer in mammals is increasing every year as a result of increased estrogen levels and increased exposure to environmental xenoestrogens. For example, the number of prescriptions of estrogen for women in menopause is rapidly increasing, presently estimated at 50,000,000 prescriptions annually in the United States alone. This increasing use of estrogen partially accounts for the higher risk of breast cancer in both young and middle-aged women. Estrogen is present in all mammals and is essential in women for reproductive organs such as ovary, uterus, breast, etc. In men, however, estrogen is required for sperm production and maturation. The abusive use of estrogen prescribed for women is at least partially responsible for the development of soft tissue cancers, especially breast cancer. It is therefore desirable to antagonize or counteract the adverse effects of estrogen in women.
The current FDA-approved treatments, e.g., tamoxifen, in the United States are effective to some extent in some of the female population in antagonizing the adverse effects of estrogen. Unfortunately, these treatments are not totally effective and may themselves cause additional health related effects, such as uterine cancer. Thus, if one could identify compounds that would make the current treatments more effective, or would work in conjunction with, or in lieu of, the present treatments, it is possible some of these adverse side effects would be alleviated or even eliminated. A possible source of alternative treatments are natural, non-toxic compounds. It is proposed that these compounds would advantageously provide for safer and more effective treatments.
The use of certain monoterpenoid plant essential oils (alpha-terpineol, linalool, and limonene) is suggested as a potential treatment for breast cancer. These monoterpenoids however are not totally effective and have been proven to be weak anti-proliferative cancer products. In addition, these data do not suggest the capability of these compounds to antagonize of action of estrogen. This may raise the question of how this product may interact in women with estrogen supplement.
Accordingly, there is a great need for novel pharmaceutical compositions containing non-toxic ingredients that may be effectively used in the prevention or treatment of soft tissue cancer in mammals.
A primary object of the present invention is to provide novel compositions that contain certain plant essential oils, natural or synthetic in source, or mixtures or derivatives thereof, as a prophylactic for, or a treatment of, soft tissue cancer.
The above and other objects are accomplished by the present invention which is directed to novel pharmaceutical compositions containing at least one plant essential oil compound, including mixtures or derivatives thereof, which are synthetically made or obtained from natural sources. The present invention is also directed to methods for using such novel pharmaceutical compositions for prophylactically or therapeutically treating soft tissue cancers.
Additional objects and attendant advantages of the present invention will be set forth, in part, in the description that follows, or may be learned from practicing or using the present invention. The objects and advantages may be realized and attained by means of the instrumentalities and combinations particularly recited in the appended claims. It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not to be viewed as being restrictive of the invention, as claimed.